Continuous rod making machines

ABSTRACT

A continuous rod making machine, especially for making cigarette filter rods includes a garniture tape passing over a garniture bed and through a tongue assembly of inverted-channel cross section positioned over the garniture bed to carry a wrapper tape and a filler into the tongue to compress the filler and form a continuous rod of filler enclosed by the wrapper tape, the tongue assembly having one or more divergent portions along its length.

United States Patent Inventor Horace A. Stone London, England Appl. No. 26,315 Filed Apr. 7, 1970 Patented Nov. 30, 1971 Assignee Molina Machine Company Limited London, England Priority Apr. 10, 1969 Great Britain [8,392/69 con'rmuous ROD MAKING MACHINES 8 Claims, 8 Drawing Figs.

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FleldotSear-eh 93/1 C, 131/84 R 831d 93/1 C; 131/84 R [56] References Cited UNITED STATES PATENTS 2,308,323 1/1943 Williams 131/84 R 3,464,421 9/1969 Pinkham et a]. 93/1 C X 3,371,000 2/1968 Davenport et al. 93/1 C Primary Examiner-Bernard Stickney AttorneyMarkva & Smith ABSTRACT: A continuous rod making machine, especially for making cigarette filter rods includes a garniture tape passing over a gamiture bed and through a tongue assembly of inverted-channel cross section positioned over the gamiture bed to carry a wrapper tape and a filler into the tongue to compress the filler and form a continuous rod of filler enclosed by the wrapper tape, the tongue assembly having one or more divergent portions along its length.

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CONTINUOUS ROD MAKING MACHINES This invention relates to continuous rod making machines and particularly to machines for making cigarette filter rods.

Known machines for producing a continuous rod of filter material contained within a wrapper, for cigarettes, comprise essentially a gamiture bed over which a gamiture tape runs to carry the wrapper and filter material, and a tongue in the region of the gamiture inlet to compress the filter material prior to the wrapper being wrapped around the compressed filter material by a folder arrangement.

It has been found with this known type of machine that there is sometimes a tendency for the filter material to be forced out from around the edges of the tongue before reaching the folding arrangement, thus giving rise to an undesirable rib running along the length of thefinished continuous rod. The present invention is concerned with dealing with this problem, although it s not limited to a machine for the production of filter rods.

According to the present invention a machine for making a continuous rod includes a gamiture tape passing over a gamiture bed and through a tongue assembly of inverted-channel cross section positioned over the gamiture bed to carry a wrapper tape and a filler into the tongue to compress the filler and form a continuous rod of filler enclosed by the wrapper tape, the tongue assembly having one or more divergent portions along its length. That is to say the cross-sectional area of the interior of each divergent portion is greater than the cross sectional area of the interior of an immediately upstream portion of the tongue. This enables any filler material which has been forced out laterally beyond the edges of the tongue to be reenclosed by the said divergent portion.

How the invention may be carried out will now be described with reference to the accompanying drawings in which:

FIG. 1 is a side elevational view partly in section of a cigarette filter rod making machine according to the invention;

FIGS. 2 to 7 are sections taken on the lines A-A, BB, C-C, D--D, E--E and F-F of FIG. 1; and

FIG. 8 is an underside perspective view of the tongue on an enlarged scale.

The filter rod making machine includes a gamiture bed 1 over which a continuous, air-pervious, gamiture tape 2 passes. A folding arrangement 3 is positioned above the gamiture bed I to fold a continuous wrapper tape around the filter material 16.

A tongue assembly, in this case comprising a single tongue 4 of inverted-channel cross section, is positioned upstream of the folding arrangement 3. A frustoconical convergent guide 5 is positioned upstream of the tongue 4 to compress the filter material which in this case is in the form of a web.

The gamiture tape 2 passes around rollers 6, 7 and 8, the roller 6 being mounted on a swinging arm so that the portion 2a of the gamiture tape 2 can be moved a limited amount in a plane substantially normal to the plane of the drawing to centralize the gamiture tape on the garniture bed 1.

The wrapper 9 passes around a roller 10 from a spool (not shown) via an adhesive-applying station (not shown) by which adhesive is applied along one edge of the wrapper. The adhesive is heat-sensitive polyvinyl acetate (p.v.a.).

The folding arrangement comprises a first folder 11 (FIG. 6) which folds over the right-hand edge of the wrapper 9.

Downstream of the first folder 11 is a second folder I2 (FIG. 7) which folds down the glued left-hand edge of the wrapper 9. A rod diameter control 18 is automatically adjustable in a vertical direction by a servomotor 13 in response to signals indicative of rod diameter from a sensor 14, to correct trends in variations of the rod diameter. The manner in which the rod diameter control 18 is adjusted is described and shown in our copending application Ser. No. 26,316 filed Apr. 7, 1970 in the name of Jan Antoni Rakowicz.

A heater 15 is positioned downstream of the diameter control 18 to heat the p.v.a. adhesive on the wrapper.

The tongue 4 has a divergent portion 17 formed by a radially outward step in the inner surface of the tongue. The internal cross-sectional area of the tongue 4 at the divergent portion (i.e. immediately downstream of the step 17) is of course greater than the internal cross-sectional area immediately upstream of the divergent portion. Moreover is should be noted that the internal cross-sectional area of the tongue drops progressively after the step in a downstream direction.

In operation, the filter material in the form of a web is fed into the guide 5 which compresses the web by folding it longitudinally sufficiently to allow the web to pass easily into the flared end 40 of the tongue 4. It may not be necessary to fit the guide 5 when using some types of filter material, such as the. type which is in the form of a tow.

As the filter web passes through the tongue 4, i.e. between the tongue 4 and the gamiture bed 1, it is progressively com pressed, except at the step. It was found in practice that with a tongue having a progressively decreasing internal cross section, i.e. without the portion 17, that the filter web tended to be forced out around the two edges of tongue at a point at or near the section BB of FIG. 1. This tendency is in fact shown in FIG. 3 where, with the tongue constructed according to the present invention, the filler web is beginning to be forced radially outwardly beyond the edges of the tongue. In order to counteract this tendency the internal cross-sectional area of the tongue is decreased more rapidly just before this point, and is then abruptly increased as shown in FIG. 8, to again bring the filter web within the confines of the two edges of the tongue.

This excessive compression and subsequent slight release of compression on the filter web could be achieved in other ways, for example, by employing two shorter tongues in series in place of the single tongue. Each of the shorter tongues would have a progressively decreasing cross-sectional area but one tongue would have its narrower end fitted into the wider end of the following tongues thus forming the portion of increased cross-sectional area.

It may be necessary to have more than one divergent portion 17 along the length of the tongue assembly.

Iclaim:

l. A machine for making a continuous rod of filler material contained within a tubular wrapper comprising:

a. a longitudinally extending garniture bed,

b. a garniture tape arranged to pass over said garniture bed while supporting a wrapper tape with a continuous stream of filler material thereon, and

c. a tongue assembly having an inverted longitudinally extending channel positioned over the garniture bed to progressively compress the stream of filler material as it is carried therebeneath and before said filler is completely enclosed by said wrapper tape,

(1. the channel of said tongue assembly having a generally diminishing cross-sectional area in the downstream direction and including at least one divergent portion intermediate the ends thereof having a tapered surface in the downstream direction and terminating abruptly to forrn'a step, said divergent portion extending transversely across the entire surface of said channel at least to the opposite longitudinal edges thereof to reduce he cross section of the channel at said divergent portion,

e. whereby said filler material is first excessively compressed and then slightly released as it passes through said divergent portion and any filler material forced radially outwardly beyond the opposite longitudinal edges of said tongue is returned within the confines of said longitudinal edges.

2. A machine according to claim 1 wherein the degree of taper of said divergent portion is substantially the same across the entire transverse surface of said channel between the 0pposite longitudinal edges thereof.

3. A machine according to claim 1 wherein the distance between the surface of the step of said divergent portion and the surface of the adjacent part of the channel downstream thereof is substantially constant at various positions between the opposite longitudinal edges of the channel.

4. A machine according to claim 1 wherein said tongue assembly comprises a plurality of longitudinally extending tongues arranged end to end, each tongue having a channel with a generally diminishing cross-sectional area in the downstream direction, the cross-sectional area of the upstream end of each succeeding tongue being greater than that of the downstream end of the next adjacent tongue to form a step between adjacent tongues.

5. A machine according to claim 1 wherein said divergent portion extends transversely beyond the opposite longitudinal edges of said channel.

6. A machine according to claim 1 adapted to making cigarette filter rods.

7. A machine according to claim 6 further comprising a convergent guide positioned upstream of the tongue assembly for receiving a web of filler material and compressing the material as it is fed from the guide into the tongue.

8. A machine according to claim 7 in which the convergent guide includes a frustoconical passage open at both ends with the smaller end downstream of the larger end and adjacent the upstream end of the tongue.

F I l l 

1. A machine for making a continuous rod of filler material contained within a tubular wrapper comprising: a. a longitudinally extending garniture bed, b. a garniture tape arranged to pass over said garniture bed while supporting a wrapper tape with a continuous stream of filler material thereon, and c. a tongue assembly having an inverted longitudinally extending channel positioned over the garniture bed to progressively compress the stream of filler material as it is carried therebeneath and before said filler is completely enclosed by said wrapper tape, d. the channel of said tongue assembly having a generally diminishing cross-sectional area in the downstream diRection and including at least one divergent portion intermediate the ends thereof having a tapered surface in the downstream direction and terminating abruptly to form a step, said divergent portion extending transversely across the entire surface of said channel at least to the opposite longitudinal edges thereof to reduce the cross section of the channel at said divergent portion, e. whereby said filler material is first excessively compressed and then slightly released as it passes through said divergent portion and any filler material forced radially outwardly beyond the opposite longitudinal edges of said tongue is returned within the confines of said longitudinal edges.
 2. A machine according to claim 1 wherein the degree of taper of said divergent portion is substantially the same across the entire transverse surface of said channel between the opposite longitudinal edges thereof.
 3. A machine according to claim 1 wherein the distance between the surface of the step of said divergent portion and the surface of the adjacent part of the channel downstream thereof is substantially constant at various positions between the opposite longitudinal edges of the channel.
 4. A machine according to claim 1 wherein said tongue assembly comprises a plurality of longitudinally extending tongues arranged end to end, each tongue having a channel with a generally diminishing cross-sectional area in the downstream direction, the cross-sectional area of the upstream end of each succeeding tongue being greater than that of the downstream end of the next adjacent tongue to form a step between adjacent tongues.
 5. A machine according to claim 1 wherein said divergent portion extends transversely beyond the opposite longitudinal edges of said channel.
 6. A machine according to claim 1 adapted for making cigarette filter rods.
 7. A machine according to claim 6 further comprising a convergent guide positioned upstream of the tongue assembly for receiving a web of filler material and compressing the material as it is fed from the guide into the tongue.
 8. A machine according to claim 7 in which the convergent guide includes a frustoconical passage open at both ends with the smaller end downstream of the larger end and adjacent the upstream end of the tongue. 